Aircraft maintenance robot

ABSTRACT

An aircraft maintenance robot (20) for maintaining aircraft surfaces is described that includes a maintenance tool (228), for example a nozzle (78), conduits and a pump, which supply fluid to the maintenance tool, which sprays the fluid on aircraft surfaces; movable arm with rotatable hinges and wrists such that a manifold to which the maintenance tools are coupled may be positioned in response to control signals; and a processor which, after accounting for the position of the aircraft, the weather conditions, and the physical dimensions of the aircraft, generates the control signals used to position the maintenance tool such that, after positioning the aircraft, the maintenance operation may be performed without human intervention. The preferred embodiment of the present invention discloses the use of the maintenance robot (20) for deicing aircraft. A wide variety of interchangeable end effectors, however, may be used for a wide variety of applications. These may include various cleaning, painting, paint removing, and even firefighting applications.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to aviation and more particularly toan apparatus and method for automatically deicing and maintaining anaircraft.

BACKGROUND OF THE INVENTION

The presence of ice on aircraft surfaces can destroy or substantiallyreduce lift, which is necessary for flight. Therefore, when icingconditions exist, the ice must be removed or prevented, generallyreferred to as "deiced," before take off. Aircraft are typically deicedby the application of a heated deicing fluid, which is usually glycol.

One present method of deicing aircraft entails using a truck or similarvehicle with an arm attached. The arm has a cradle at the end from whichan operator positions the arm and sprays deicing fluid on the surfacesof the aircraft. This method has several inherent disadvantages. First,this method requires considerable time to deice the aircraft.Additionally, waste of deicing fluid frequently results from theapplication of excessive amounts of deicing fluid. Moreover, human errorin positioning and applying the deicing fluid is more probable,especially since the greatest need for deicing typically occurs in theharshest weather conditions. The human error and excessive amounts ofdeicing fluid expose operators to direct contact with the potentiallydangerous chemicals in the deicing fluid.

Another method of deicing aircraft involves using a truck or similarvehicle with a arm attached thereto, and the arm positioned by remote.An operator views a monitor coupled to the arm, and based on the viewfrom the remote camera, the operator positions the nozzles and spraysthe surfaces. This method suffers from the same deficiencies as theprior system, but even less effectively deices the aircraft because theoperator only views the aircraft surface through the remote videocamera. If it is not possible to see in through the video camera, theoperator will erroneously determine that the surface is free of ice.

A system is therefore needed to automatically deliver heated deicingfluid to the surfaces of aircraft in a short time, without waste ofdeicing fluid, and without error caused by human operators.

SUMMARY OF THE INVENTION

The present invention provides an automatic robotic deicing apparatusand method designed to satisfy the aforementioned needs. The deicing iscarried out by an automatic, robotic deicing robot having a manipulablearm with nozzles for spraying deicing fluid. The present invention mayalso be used to perform other basic maintenance tasks on aircraftsurfaces.

According to one embodiment of the present invention, deicing fluid isdelivered to nozzles which are attached to a free end of an armcomprised of a plurality of arms responsive to control signals generatedby a microprocessor. The microprocessor generates the control signalsafter accounting for the position of the aircraft, the dimensions of theaircraft, and the weather conditions. Deicing fluid may then bedelivered to the surfaces of the aircraft without substantialintervention of a human operator.

According to another embodiment of the present invention, a recoveringand reconditioning system is provided such that a portion of the deicingfluid sprayed on the surfaces of the aircraft may be recovered andreconditioned for re-use.

According to another embodiment of the present invention, a maintenancetool is coupled to a free end of an arm comprised of a plurality of armsthat are responsive to control signals generated by a microprocessor.This arrangement allows the maintenance tool to follow the surfaces ofthe aircraft in close proximity such that the aircraft may be washed,inspected by video, depainted or deiced depending on the particularmaintenance tool coupled to the free end of the plurality of arms,without substantial intervention of a human operator.

According to another aspect of the present invention, there is provideda method for deicing aircraft comprising the steps of preparing thedeicing fluid for application; generating control signals that accountfor the size of the aircraft, the position of the aircraft in thedeicing area, and the weather conditions. Then, the robot positions thenozzles to deliver the deicing fluid in response to the control signalssuch that the deicing fluid may be delivered to the surfaces withoutsubstantial intervention of a human operator.

The method and apparatus for automatically deicing aircraft provideseveral technical advantages. The method and apparatus eliminate theneed for substantial human intervention by an operator and,consequently, the inherent disadvantages of a human operator, includingexcess deicing time, operation inefficiency, and human error. Theautomated delivery of deicing fluid to aircraft surfaces means thatconsistent deicing would occur despite harsh weather conditions.Additionally, the use of an automated, robotic arm allows placement ofthe nozzles in close proximity to the aircraft surfaces, which furtherreduces the waste of deicing fluid and maintains the heated temperatureof the deicing fluid. Additionally, the automated, robotic deicer allowsfaster application of deicing fluid to the surfaces of an aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be acquiredby referring to the detailed description and claims when considered inconnection with the accompanied drawings in which like reference numbersindicate like features and wherein:

FIG. 1 is a perspective view of the aircraft maintenance robot of thepreferred embodiment applying deicing fluid to a typical commercialaircraft;

FIG. 2 is a schematic, elevational view of the maintenance robot;

FIG. 3 is a schematic side view of the manifold;

FIG. 4 is a schematic top view of the manifold;

FIG. 5 is a side view of the arm;

FIG. 6 is a schematic, cutaway, side view of the maintenance robotchassis;

FIG. 7 is a schematic, cutaway, top view of the aircraft maintenancerobot chassis base;

FIG. 8 is a schematic, cutaway, bottom view of the aircraft maintenancerobot chassis base;

FIG. 9 is a schematic side view of the operations center in the travelmode;

FIG. 10 is a schematic side view of the operations center in theoperations mode;

FIG. 11 is a block diagram of the processing and communications for theaircraft maintenance robot;

FIG. 12 is a schematic front view of the control panel for the aircraftmaintenance robot and other equipment located in the operations cabin;

FIG. 13 is a side view of a multiplicity of exemplary maintenance tools;

FIG. 14 is a schematic top view diagram of the deicing of a commercialaircraft over an elapsed time period for one deicing cycle;

FIG. 15 is a schematic top view showing the configuration of aircraftmaintenance robots when four robots are used; and

FIG. 16 presents a flowchart of an exemplary process for deicing acommercial aircraft with the aircraft maintenance robot.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of the present invention is best understood byreferring to FIGS. 1-16 of the drawings, like numerals being used forlike and corresponding parts of the various drawings.

FIG. 1 provides an illustrative drawing showing the aircraft maintenancerobot 20 of the preferred embodiment applying a deicing fluid to atypical commercial aircraft 22 on an airport runway. The deicing fluidmay be heated or at ambient temperature depending on the particularchemical compound being used. According to FIG. 1, aircraft maintenancerobot 20 comprises chassis 24, which includes mast 26 and chassis base28. From chassis base 28, tracks 30 and 32 provide both support and away to move the aircraft maintenance robot 20. On mast 26 is arm 34,comprising arms 36 and 38, which attaches to arm support trunnion 40.Extending from mast 26, inner arm 38 attaches to trunnion 40 and toelbow 42. Additionally, outer arm 36 attaches to elbow 42 and, at theopposite end, includes manifold, or end effector, 44. Manifold 44comprises a plurality of nozzles 78 (not shown) through which deicingfluid 46 may flow to commercial aircraft 22. As FIG. 1 illustrates, arm34 may take a variety of positions along mast 26, and arm 34 may take agreat number of positions to fully apply deicing fluid 46 to commercialaircraft 22.

Referring to FIG. 2, aircraft maintenance robot 20 includes chassis base28, to which mast 26 is attached. Movable robotic arm 34 is attached totrunnion support 40 (not shown). Support trunnion 40 slides within guide48 in mast 26 from the uppermost position 50 to the lowermost position52, and to maintain isolation between the outside atmosphere and theinternal mechanics of mast 26, seal 54 extends the length of guide 48and may comprise a rubber material or brush configuration. Aircraftmaintenance robot 20 also includes indication lights 56 and 58.Indication light 56 may comprise a rotating light, similar to that oftenfound on moving objects on the airfield, to indicate movement ofaircraft maintenance robot 20. Indication light 58 may be red or someother color to indicate operation or movement of a robotic arm 34. Atthe lower portion of the aircraft maintenance robot 20 and located onchassis base 28 are indication lights 60, 62, 64 and 66, which indicateoperation of the unit. Along the side of the lower chassis base 28appears inlet 68 for providing air to an internal gas turbine engine122. Although the preferred embodiment uses a gas turbine engine 122 forprime movement, other similarly compatible forms of locomotion areconsidered within the scope of the present invention. Near the bottomedge of chassis base 28 are bumper guards 70 to prevent damage toaircraft maintenance robot 20 or other structures or equipment in theevent of inadvertent contact between them and aircraft maintenance robot20. Located near the top of mast 26 appears antenna 72 for transmittingdata to and from aircraft maintenance robot 20.

Inner arm 38 is attached to trunnion 40 at one end and elbow 42 at theother, to which outer arm 36 is also attached. The end of outer arm 36,opposite to elbow 42, is manifold 44 and wrist 74. Near wrist 74 onouter arm 36 appears camera 76. Camera 76 may be an infrared camera,thermographic scanner, ultrasonic sensor, video camera, or anyappropriate sensor or viewing device for various viewing and sensingapplications.

Referring now to FIG. 3, there is shown a side view of manifold 44.Outer arm 36 of arm 34 is coupled to manifold 44 at wrist 74. Nozzles 78(not shown) are coupled to manifold 44 in such a way as to allowspraying of fluids away from manifold 44. In addition to nozzles 78,proximity sensors 79 are coupled to the manifold 44. The proximitysensors 79 are a safety feature which automatically will disable the arm34 if the manifold 44 is too close to an aircraft surface.

Referring now to FIG. 4, there is shown a top view of manifold 44. Wrist74 couples outer arm 36 (not shown) and manifold midsection 80. Manifoldextensions 82 and 84 are slidably connected to manifold midsection 80such that the size of manifold 44 may be varied. Manifold extensionactuators 86 and 88 are operable to slide in and slide out of manifoldextensions 82 and 84 into or out of midsection 80, allowing for avariation of the size of manifold 44. The unexpanded size of themanifold 44 may be used to deice small aircraft.

Referring now to FIG. 5, a side view of the arm 34 is shown. Wrist 74 islocated on the end of outer arm 36, which is also coupled to inner arm38 at elbow 42. Inner arm 38 is also coupled to support trunnion 40.Near the connection of support trunnion 40 to inner arm 38 appears aportion of deicing fluid conduit 90, which enters inner arm 38 neartrunnion 40 and runs the length of arm 34 through wrist 74 into nozzles78 located on manifold 44. Also entering inner arm 38 near trunnion 40is camera linkage 92, which couples the camera 76, located on outer arm36, with monitor 96 (not shown) and VCR 98 (not shown). Camera link 92may be, for example, electrical linkage or fiber optics. Entering innerarm 38 near trunnion 40 is also control signal lines 94, which coupleactuators in the arm and manifold to a first processor 100 (not shown).Trunnion 40 is coupled to inner arm 38 at rotatable hinge 102. Rotatablehinge 102 has an actuator 104 (not shown), which can rotatably moveinner arm 38 about rotatable hinge 102 in response to control signals192, developed by first processor 100 and carried by control signallines 94 to actuator 104. Similarly, actuator 108 (not shown) located atrotatable hinge 42 allows outer arm 36 to be rotatably moved aboutrotatable hinge 42 in response to control signals 192. Wrist 74 containsactuator 110, which can move the wrist in two axes in response tocontrol signals 192 developed by the first processor 100.

Now referring to FIG. 6, there is schematically shown a cutaway sideview of the chassis 24 of the aircraft maintenance robot 20. Inner arm38 is associated with rotatable hinge 102, which may be raised andlowered in guide 48 on mast 26. Deicing fluid conduit 90 enters innerarm 38 near rotatable hinge 102. Deicing fluid conduit 90 allows thetransport of deicing fluid 46 from pump 112 to nozzles 78. Adequatedeicing fluid conduit 90 is provided such that slidable hinge 102 mayslide full travel in guide 48 from the uppermost position 50 (not shown)to the lowermost position 52 (not shown). Pump 112 is associated withdeicing fluid reservoir 114, which is in fluid communication with pump112. Deicing fluid reservoir 114 may be filled with deicing fluid 46through filling port 116. Filling port 116 may be connected to a truckof deicing fluid (not shown) or may be connected to a fluid farm 118(not shown).

Now referring to FIG. 7, there is shown a cutaway top view of chassisbase 28 of the aircraft maintenance robot 20. Near the middle of chassisbase 28 is deicing fluid reservoir 114. Deicing fluid reservoir 114 inthe preferred embodiment has heating elements 120 (not shown) and maycontain approximately 8000 gallons of deicing fluid in the preferredembodiment. The heating elements 120 allow the deicing fluid 46 to bemaintained at high temperatures, as high as 210° F. Located to one sideof deicing fluid reservoir 114 is turbine generator 122. The air neededfor turbine generator 122 is provided through air intake 124 and exhaustexits through exit port 126. The turbine generator 122 is capable ofproviding all necessary energy for operation of the aircraft maintenancerobot 20, but external power may be accepted, as well. Located to oneside of air intake 124 is hydraulic pad 128, on which may rest hydraulicreservoir 130 (not shown) and hydraulic pump 132 (not shown). Adjacentto hydraulic pad 128 and deicing fluid reservoir 114 is pump pad 134, onwhich rests pump 112. Located near pump pad 134 is arm mounting pad 136,upon which arm 34 and part of mast 26 are mounted. Opposite arm mountingpad 136 and near exhaust port 126 appears power source connection 138,which allows for external power to be used by the aircraft maintenancerobot 20. The aircraft maintenance robot 20 may operate with externalpower provided through power source connection 138 or on powerinternally produced by turbine generator 122.

Located to one side of the chassis base 28 is processor compartment 144,which is separated from the rest of the base 28 by insulating divider146. In the corner of the processor compartment 144 is the firstprocessor 100, which is the main processor for controlling maintenanceoperations performed by the aircraft maintenance robot 20. Adjacent tothe first processor 100 is the backup first processor 140. Backupprocessor 140 will assume responsibility for controlling operations ofthe aircraft maintenance robot 20 in the event of a failure of the firstprocessor 100. A second processor 142 is located on the other side ofbackup first processor 140. The second processor 142 may be connected toweather transducers 148 (not shown), from which it may develop weatherinformation. The second processor 142 then may communicate to firstprocessor 100 the weather information. Located near second processor 142is communications transceiver 150, which is coupled to antenna 72.Communications transceiver 150 allows for the receiving and transmittingof data by telemetry.

Now referring to FIG. 8, there is shown a schematic, cutaway bottom viewof chassis base 28. Located near the middle section of chassis base 28,as seen from below, is fuel tank 115. Fuel tank 115 may be a reservoirholding approximately 150 gallons of fuel. To each side of fuel tank 115are tracks 30 and 32. Tracks 30 and 32 allow the aircraft maintenancerobot 20 to have bilateral movement, as well as the ability to turn themaintenance robot 20 by individually actuating one of the trackingmotors 152. Tracking motors 152 may include DC motors and gearboxes 154and 156. The tracks 30 and 32 are much like the tracks on a bulldozer ortank.

Referring now to FIG. 9, there is shown an operations center 156, fromwhich the aircraft maintenance robot 20 is monitored and initiated. FIG.9 shows the operation center 156 in the travel mode. On the roof ofoperations cabin 168, located on operations center base 166, are antenna158 and weather transducer 160. Antenna 158 allows communication withthe aircraft maintenance robot 20, with pilots of commercial aircraft22, and with the airport facility. Weather transducer 160, along withothers not shown, allow weather information to be checked by theoperator. Maintenance operations by the aircraft maintenance robot 20may be viewed by the operator through side glass 162.

Now referring to FIG. 10, there is shown a side view of the operationscenter 156 in the operations mode. The operations center 156 issupported by and may be transported by tracks 164. Operations centerbase 166 rests on tracks 164. Rotatably coupled to operations centerbase 166 are hydraulic strut 172 and beam 170. Beam 170 is alsorotatably coupled to operations cabin base 176. Hydraulic strut 174 isrotatably coupled to operations cabin base 176 and to beam 170. Thesupport structure of the operations cabin comprised of hydraulic struts172 and 174 and beam 170 is operable to raise and lower the operationscabin by actuating hydraulic struts 172 and 174. Located on the side ofoperations cabin 168 are air intakes 178, which provide air to a turbinegenerator 182 (not shown). Turbine generator 182 is capable of providingall necessary energy for operations cabin 168. External power may alsobe used and may be imported through external power connection 184. Alsolocated on the side of operations cabin 168 is heating, ventilation, andair conditioning unit 180.

The ability to raise and lower the operations cabin 168 with hydraulicstruts 174, 172 and beam 170 allows a travel mode and an operationsmode, which make operation of the maintenance robot system moreconvenient and safer. The operations cabin 168 can be placed in thetravel mode, which provides a low center of gravity for more stabilityin moving. Additionally, the travel mode may be selected when therobotic system is not in use or when an emergency exists for an incomingaircraft such that the number of vertical hazards on the airfield isreduced.

Now referring to FIG. 11, there is shown a schematic block diagram ofthe processing and communications for the maintenance robot 20. Thesecond processor, or weather processor, 142 produces weather informationin response to signals received from weather transducers 148, and theweather information is communicated to the first processor 100.Information from position transducer 188 (not shown) is transmitted tothe first processor 100; the transmission of the signal from positiontransducer 188 into first processor 100 is represented by numeral 190.The signal to begin deicing and the dimensional code are received by thecommunications transceiver 150 from the operations center 156 andtransmitted to the first processor 100. Signal 190, the weatherinformation from second processor 142, the dimensional code, and thesignal to perform deicing are also received by the backup firstprocessor 140. Additionally, all the information being received byprocessor 100 is displayed on the main terminal 186 in the operationscenter 156. In the event of a failure of processor 100, backup firstprocessor 140 is able to take over control of the maintenanceoperations. In normal operations, after having received the positiontransducer signal 190, the weather information from second processor142, the dimension code, and start signal from the communicationstransceiver 150, the first processor 100, or backup first processor ifthe first processor 100 fails, develops control signals 192 to becarried to the various actuators by control signal lines 94.

Referring now to FIG. 12, there is shown a front view of control panel194 and equipment accessible by the operator in the operations cabin168. To one end of control panel 194 appears a first keyboard 196 formanually entering weather information. Located on the control panel 194near the first keyboard 196 are manual controls 198 and 200, which allowfor a manual override of the control signals 192 generated by the firstprocessor 100 or the backup first processor 140. Located on the controlpanel 194 near the manual controls 198 and 200 appears an abort switch202. The abort switch 202 provides for an immediate halt of alloperations and may be programmed to signal the aircraft maintenancerobot 20 and the operations center 156 to move to some specified safetyarea. A ball track, or "mouse," 204 also appears on the control panel194 and allows for movement of a cursor on the main terminal 186.Control panel 194 also contains an ON button 206 and a START button 208.The ON button 206 powers up the unit, and the START button signals firstprocessor 100 to start a deicing cycle. Near START button 208 is asecond keyboard 210 for entering a dimension code. Below the secondkeyboard 210 appears an ENTER button 214 for entering data on thecomputer. Associated with the control panel 194 is microphone 216 foruse with the communications transceiver 150 or when talking to pilots orground crew. Also associated with control panel 194 and other equipmentin the operations cabin 168 is power seat 218. From power seat 218, theoperator may operate control panel 194, main terminal 186, and otherequipment of the to address ergonomic accommodations for operatorcomfort.

Additional equipment found in the operations cabin 168 and shown in FIG.12 include main terminal 186, supplemental terminal 222, VCR 98 andprinter 226. Main terminal 186 displays information entered andtransmitted to the aircraft maintenance robot 20. Supplemental terminal222 may be used to display additional information from the firstprocessor 100 or the second processor 142, such as weather information.Supplemental terminal 222 may also take video from camera 76 in place ofmonitor 96 (not shown). VCR 98 is coupled to camera 76 to recordapplication of deicing fluid 46 to the surfaces of commercial aircraft22. Printer 226 is associated with control panel 194 and first processor100, and provides a means for producing a hard copy record of theexisting weather conditions and the completion of a specified aircraftidentified by tail number.

Now referring to FIG. 13, there are shown examples of maintenance tools228, which can be attached to manifold 44 so that the aircraftmaintenance robot 20 may accomplish different maintenance tasks. Thelower left corner of FIG. 13 shows nozzle 78 for deicing aircraft. Inthe upper left hand corner of FIG. 13, there is shown a video inspectionprobe 230. This probe 230 may be installed in manifold 44 for performingvideo inspections of aircraft surfaces. Video inspection probe 230 mayalso be a probe which allows inspection of aircraft surfaces with theuse of X-ray. The upper righthand corner of FIG. 13 shows depaint nozzle232 for the application of substances to remove paint from the surfacesof aircraft. The bottom righthand corner of FIG. 13 shows a washingnozzle 234 for cleaning commercial aircraft 22. Other maintenance tools228 may be attached to manifold 44 to carry out other tasks; forexample, a maintenance tool 238 could be attached to manifold 44 forfirefighting.

Referring now to FIG. 14, there is shown an elapsed time, schematic topview of the deicing of a commercial aircraft 22 by two aircraftmaintenance robots 20. The commercial aircraft 222 taxies up and ispositioned in the reference position 236. The operator in the operationscenter 156 enters the tail number or a dimensional code on the controlpanel 194 with second keyboard 210. The information is transmitted tothe aircraft maintenance robots 20, and their first processors 100retrieve the proper envelope for that specific aircraft; the envelope isan imaginary covering for the commercial aircraft 222 of a giventhickness such that, if the robotic arm traces out the envelope, it willremain within a given distance of the aircraft surfaces. The firstprocessor 100 also receives weather information from the weathertransducers 148. Second processor 142 possesses all of the functionalcapability of final processor 100 and serves as a ready back-up if firstprocessor 100 should fail. Additionally, the first processors 100receive information from positioning transducers 188. The basic steps ofthe deicing then begin.

The first processor, having received the go-ahead from the operator inthe operations center 156, the weather information and the positioninginformation, then generates control signals 192 such that the arm 34 israised on the mast 26 to a height above the top of the wing surfaces,beginning at position one 238. The first processor generates controlsignals 192 so that the tracking motors 152 are operated long enough tomove the maintenance robots 20 to position two 240. Considering now theaircraft maintenance robot 20 on one side of the aircraft 22, the firstprocessor 100 generates control signals 192 which position the manifold44 with the arm 34 within a specified distance of the surface of theaircraft 22. The first processor 100 generates control signals 192 suchthat the manifold 44 with nozzles 78 delivers deicing fluid 46 to theaircraft nose at position two 240 and then moves the maintenance robot20 toward the empennage, or tail of the aircraft 290. The application ofdeicing fluid to aircraft is a continuous smooth process in whichdeicing robot 20 smoothly graces the aircraft 22 surface. Although thefollowing discussion details various positions, the positions are forreference or orientation only and do not reflect starts or stops inrobot 20 motion along the aircraft 22 fuselage.

At position three 242, the first processor 100 develops control signals192 so that deicing fluid 46 is similarly delivered to the surfaces ofthe aircraft for that section. After deicing the next section, themaintenance again moves robot 20 toward empennage 290. Upon reaching thewings, shown in FIG. 14 as position four 244, the processor 100generates signals such that the manifold 44 is positioned to deliverdeicing fluid 46 to the fuselage 246, and then the manifold is rotatedsuch that nozzles 78 are parallel to the surface of the wing, and thearm is moved away from the fuselage 246 until reaching the wingtip 248.After reaching the wingtip, the maintenance robot 20 is moved onemanifold width toward the empennage 290. The arm is then moved towardsthe fuselage 246 until it gets within a specified distance of thefuselage 246. The arm then stops moving and is rotated such that theplane formed by the nozzles 78 is parallel to a line tangent to a crosssection of the fuselage 246 and perpendicular to fuselage 246. Themanifold 44 is then positioned by the arm 34 and wrist 74 such that ittraces the fuselage 246, delivering deicing fluid 46 to the surfacesthereof.

After delivering deicing fluid 46 to the surfaces of that section, thefirst processor 100 sends the necessary control signals 192 to thetracking motors 152 to move one manifold width towards the empennage,stopping at position five 250. Similar steps for deicing the fuselageoccur at position five 250 and position six 252. Upon reaching therudder and stabilizer, shown at position seven 254, the first processor100 positions the manifold with the arm to deliver deicing fluid 46 tothe rudder 256, but not raising the manifold above the height of thelowest point on the stabilizer 258.

The commercial aircraft 22 shown in FIG. 14 has a "T" tail, which meansthat the stabilizer is attached to the rudder at the top so that therudder is the vertical of a "T", and the stabilizer is the horizontal ofthe "T". After delivering deicing fluid to the rudder 256, the firstprocessor 100 produces control signals 192 to move manifold and arm awayfrom the rudder adequately to clear the outer edge of the stabilizer258. Then the manifold is raised and positioned to deliver deicing fluid46 to the top surface of the stabilizer 258.

After delivering the deicing fluid 46 to the stabilizer 258, the firstprocessor 100 produces the control signals 192 such that the trackingmotors 152 move the maintenance robot 20 to the ready position in therear, position eight 260. Upon reaching eight 260, the operator issignalled that deicing is complete and indicator lights 62 and 60 areturned on. Additionally, after completion of deicing, robot 20 mayreturn to a docking station for refueling or storage.

Now referring to FIG. 15, there is shown a schematic, top view of acommercial aircraft 22 with placement of four aircraft maintenancerobots 20. The configuration of FIG. 15 would work similarly to theprocess explained in conjunction with FIG. 15, except each of theaircraft maintenance robots 20 would be responsible for only one-fourthof the surfaces of the commercial aircraft 22.

A better understanding of an exemplary deicing cycle is represented inthe flowchart in FIG. 16. The commercial aircraft 22 may be consideredto have taxied into reference position 236. Operator in the operationscabin 168 then starts the process. Starting point 266 of the FIG. 16flowchart represents this step. The first processor 100 then reads andstores the weather information in step 268. The first processor 100 thensets the proper weather mode for the particular deicing cycle at step270. Then, the processor reads the dimension code at step 272, and basedon the dimension code, retrieves the proper envelope at step 274. Then,processor 100 reads the position information for aircraft 22 at step276. The next step is for processor 100 to determine whether aircraft 22is in an acceptable position with regard to reference position 236, step278. If not, processor 100 sounds an alarm and turns on a warning signallight at step 280 and then stops the deicing cycle at step 282.

If processor 100 decides that aircraft 22 is in an acceptable positionwith regard to reference position 236, processor 100 generates controlsignals 192 to raise the manifold and arm 34 above the height ofaircraft 22 wings at step 284. The next step, at 286, is to turn on thetrack motor to move the manifold to the end farthest from empennage andeven with the nose of aircraft 22.

With robot 20 in position, the process entails turning on the VCR andpump at step 288 and to begin spraying the fuselage at step 290. In acontinuous flowing motion robot 20 manipulates the manifold consistentwith the aircraft dimensions as determined by the aircraft dimensioncode. This is step 292 of FIG. 16 during which robot 20 causes themanifold to move about the aircraft 22 fuselage in a continuous flowingmotion from the nose to the empennage. During this process, processor100 queries whether deicing is occurring properly to remove ice from theaircraft 22 at step 294. This may be done by any of the methods ordevices described above. If deicing is not properly occurring, processor100 at step 296 adjusts the speed of robot 20, or the fluid flow ortemperature to achieve proper deicing at 296. Otherwise, processor 100continues to query whether the trailing edge of aircraft 22 has beenreached at step 298. When this occurs, the pump and VCR are turned offat step 300. Processor 100 then prints out the weather mode, tail numberand time or other pertinent information at step 302 and updates robot 20location at 304. An audible announcement for completion of deicingoccurs at step 306 at this point. Finally, processor 100 ends thedeicing process at step 308.

It is to be understood that the preceding process was for onemaintenance robot 20 in a preferred embodiment which involves twomaintenance robots. The process for maintenance robot 20 on the otherside would be similar to the process presented. Additionally, thepreferred embodiment includes the ability to perform the precedingprocess in reverse, beginning with the maintenance robot 20 in the rearposition and moving toward the nose of aircraft 22.

Although the present invention and its advantages have been described indetail, it should be understand that various changes, substitutions, andalterations may be made herein without departing from the spirit andscope of the invention as defined in the appended claims.

What is claimed is:
 1. A robotic aircraft deicer for distributingdeicing fluid to surfaces of an aircraft, comprising:nozzles forspraying the deicing fluid on the surfaces of the aircraft; deliveringmeans for delivering the deicing fluid to said nozzles; positioningmeans for positioning said nozzles to deliver the deicing fluid to thesurfaces of the aircraft; and control means coupled to said positioningmeans and operable to automatically control said positioning means suchthat the deicing fluid may be delivered to the surfaces of the aircraftwithout substantial intervention of a human operator, said control meanscomprising:a first processor; means for entering physical dimensions ofthe aircraft into said first processor, said first processor operable togenerate a plurality of control signals in response to entry of saiddimensions into said first processor; means for entering weatherinformation into said first processor, said first processor operable toadjust said control signals to account for said weather information; andmeans for transmitting said control signals from said first processor tosaid positioning means.
 2. The deicer of claim 1, wherein saiddelivering means for delivering said deicing fluid comprises:a reservoiroperable to store deicing fluid; a heater fluidly connected to saidreservoir and operable to heat portions of said deicing fluid; and apump fluidly connected to said reservoir, said heater and said nozzlesand operable to pump said portions of the deicing fluid from saidreservoir to said heater and from said heater to said nozzles.
 3. Thedeicer of claim 1, wherein said positioning means comprises:a pluralityof arms linked at the ends, said plurality of arms having a first andsecond free end; manifolds associated with said first free end of saidarms and said nozzles coupled to said manifolds; said arms responsive tocontrol signals from said control means; a wrist coupled to said firstfree end of said arms and coupled to said manifolds and operable toallow pivotal motion of said manifold and responsive to control signals;said manifolds operable to allow telescoping of said manifolds; and abase containing a guide and coupled to said second free end of saidplurality of arms such that said second free end of said plurality ofarms is movable in said guide.
 4. The deicer of claim 3, and furthercomprising:a reference position; means for accounting for the positionof the aircraft about at least two axes in an area for deicing withrespect to said reference position; and means for adjusting said controlsignals from said first processor to account for variations from saidposition of the aircraft with respect to said reference position.
 5. Thedeicer of claim 4, wherein said means of positioning said aircraft insaid reference position comprises:transducers operable to sense locationof an aircraft within said deicing area and to produce signalscorresponding thereto; and signals from said transducers transmitted tosaid first processor.
 6. The deicer of claim 3, and further comprisingmeans for recording delivery of said deicing fluid.
 7. The deicer ofclaim 6, wherein the said means for recording delivery of said deicingfluid comprises:a video camera coupled to said first free end of saidarms; a monitor coupled to said video camera, said monitor and saidvideo camera operable to view surfaces of the aircraft and theapplication of deicing fluid to said surfaces; a video recorder coupledto said video camera; and a printer coupled to said first processor. 8.The deicer of claim 3, wherein the said control means furthercomprises:means for overriding said control signals from said firstprocessor; and means for manually generating said control signals. 9.The deicer of claim 3, wherein said means for entering weatherinformation comprises:weather transducers; a third processorelectrically coupled to said weather transducers and operable inconjunction with said weather transducers to generate weatherinformation; means for overriding said weather transducer signals; meansfor accepting weather information from airport weather facility; meansfor selecting weather information from said third processor or from theairport facility; and means for transmitting said selected weatherinformation to said first processor.
 10. The deicer of claim 3, andfurther comprising means for transporting said deicing unit.
 11. Thedeicer of claim 3, and further comprising the means for producing allnecessary power for the deicer.
 12. The deicer of claim 1, and furthercomprising means for recovering and reconditioning a portion of thedeicing fluid sprayed on the surfaces of the aircraft.
 13. The deicer ofclaim 12, wherein said means of recovering the deicing fluid comprises:acollector located outwardly adjacent to aircraft and operable to collecta portion of the deicing fluid; reservoirs; filtering means forfiltering the deicing fluid operable to filter unwanted solid particlesin the recovered deicing fluid; a chemical separator operable toseparate the deicing fluid from other liquid substances therein anddistribute the separated deicing fluid and recovered substances otherthan deicing fluid to said reservoirs; new deicing fluid in saidreservoirs; a mixing chamber wherein the recovered deicing fluid and newdeicing fluid from said reservoirs are mixed; a pump; a conduit fluidlyconnected to said collector, said filtering means, said separator,mixing chamber, said pump, and said reservoirs; a second processor; amultiplicity of valves coupled to conduit and responsive to said controlsignals operable to control flow of fluids in the various branches ofsaid conduit; said second processor operable to produce said controlsignals to said valves and said pump such that recovery andreconditioning occur substantially without human intervention.